The quantum number which explains the line spectra observed as doublets in case of hydrogen and alkali metals and doublets and triplets in case of alkaline earth metals is

When the same amount of zinc is treated with excess of H₂SO₄ and with excess NaOH, the ratio of the volume of H₂ evolved is

The gas that is used for sterilizing water is

In photoelectric effect, if the energy required to overcome the attractive forces on the electron,(work functions) of Li, Na and Rb are 2.41eV, 2.30eV and 2.09eV respectively, the work function of ‘K’ could approximately be in eV